Theme CSS preventing some changes to styling through APR options

I downloaded the Bonfire them through my Envato Elements account and am using the Bonfire-child theme.

I have been trying to use APR options to modify the styling of some of the items within a site I am currently working on e.g. Breadcrumbs (Padding, background colour, font colour etc) however whilst the styles are being added to they appear to be being overridden by style settings in theme.css.

Do you know what might be causing this or if there is a way I can override theme.css by adding a copy to the same path within the child theme?

About ArrowPress

ArrowPress.net is among outstanding in-house services that ARROWHITECH JSC has developed on our way to widen our skills and reputation in the world of innovative IT.

ArrowTheme focuses our customer on prominent and high-end themes specializing in the most popular CMS to date, it's WordPress CMS which is promoted and sold on the well-known Envato marketplace Themeforest.net.